Hidden characters:
Peelgood
Sarge
Jack
Ice
Thunder
Slyck
Spike
Top speed:
Random character:
Enter the following codes on the game selection screen:
Butch
Enable all hidden characters:
Hold L and press X, R, A, X, R(2).
Hold Down/Left, then press B, Y(2), A, Y.
Hold X, then press L(2), Up, Down, Left, Down.
Hold Up, and press A(2), R(2), Y, A.
Hold B, and press Up, L(3), Right.
Hold Up/Left, and press Y, B, X, B(2), X, A.
Hold Y, and press L(2), Up, L, Left, R.
Hold R, and press X, B(2), A, Y, Left, A.
Hold L + X, and press Up(2), Select, Up(2), Right.
Hold Y, and press L(2), R, Down, Left, R at the game start screen. The speed may now be set to ten in the options screen.
Press R + L at the character selection screen.